Permanent waving of hair



United States Patent 2,976,215 PERMANENT WAVING OF HAIR Gregoire Kalopissis and-Andre Viout, Paris, France, as- "signors to Socit Anonyme dite Societe MonsavonlOreal, Paris, France, a corporation of France No Drawing. Filed Apr. 9, 1959, Ser. No. 805,135 Claims priority, application France Apr. 17, 1958 9 Claims. c1. 16787.1)

. This invention relates to processes for the permanent waving of hair and to novel compounds useful in such processes.

The most common processes for the permanent wavhair is impregnated with an aqueous solution containing one or more sulphydryl compounds, such for example as mercaptoalkanoic acids, employed as reducing agents for the SS linkages of the keratin, in order to impart the hair the desired plasticity so as to permit reshaping.

While kept in the form of aqueous solutions, the aforesaid compounds which contain a free -SH group tend to decompose and to evolve hydrogen sulphide and other products of disagreeable odour. Of these compounds, only thioglycollic acid is used in practice.

In order to obviate the aforesaid disadvantages, it has already been proposed to block'the SH group of these mercaptoalkanoic compounds by substituting for the hydrogen atom another group which can bereadily eliminated by simple hydrolysis in alkaline medium. Thus, French Patent No. 999,436 proposes the use of compounds of the general formula:

in which R represents a hydrogen atom or an alkyl group, and X an amino, alkyl, or alkoxy group. However, such'compounds are not well adapted to standard practice,-since, in order to obtain hydrolysis of the alkaline solution and to makeit ready for use, it is necessary to heat it to about 95 to 100 C. andithento have it cooled, It is not possible to effect the hydrolysis of such compoundsafter their application to the hair since the quantity of alkali, e.g. ammonia, necessary to achieve the hydrolysis, at the beginning thereof, causes the solution to exceed the narrow operativepH limits (from 9 to 9.8) within which the liberated thioglycollic acid derivative is. effective without being a depilatory.

There have also been employed, in the first step of permanent waving, amides of 'thioglycollic acid having the general formula HSCH CONHR, where R is hydrogen, a lower alkyl residue or a lower hydroxyalkyl residue. good results in a fairly wide pH range (from 6 to 9), in regard to the quality of the wave obtained, such amides have the major disadvantage of being more unstable thanthioglycollic acid. Accordingly, they more readily liberate, on storage, a quantity of hydrogen sulphide such that the product becomes substantially unusable. Moreover, they tend to produce lesions on the hands of operators who repeatedly use them. 1

Itis possible to aovid or minimise the disadvantages inherent. in. these amides, while retaining the possibility of obtaining a good wave, by using, for softening the keratin ofthe hair, S-acyl derivatives of these amides, said derivatives being novel chemical compounds per se.

However, while the latter type of amide gives ing of hair ordinarily comprise a first step in which the and may even reach' the theoretical (e.g. maximum) ice According to a first object of the present invention there are provided novel compounds suitable for use for the softening of the kertain of the hair and having the 1 general Formula I:

R-CO--S-'CH(R )C0-NHR I inwhich R represents a lower alkyl or carboxyalkyl residue, and R and R each represent a hydrogen atom or' a lower alkyl residue.

A further object of the invention is a process for the so-called permanent waving of hair wherein the hair is impregnated with an aqueous solution of a mercapto compound, constrained to a desired configuration and set in that configuration, wherein the mercapto compound used is an amide of general Formula L Aqueous solutions of S-acyl-mercapto-amides according to the invention contain substantially no free -SH groups, but they undergo hydrolysis in the presence of ammonia, an organic base such as an ethanolarnine, e.g. triethanolamine, or even an inorganic base, to give meroaptoamides useful as softening agents for the keratin, the hydrolysis being promoted by heating. This hydrolysis, on which the permanent waving processof the invention'is framed, has been carefully studied..

It has been found that, either as a function of the concentration of the base employed, or as a function of the temperature at which the hydrolysis is carried out, or again as a function of these two factors together, the degree ofhydrolysis obtained varies within wide limits,

value in some cases, within an extremely short .period of time, for example one minute. Such a high rate of hydrolysis has made it possible to use the said compounds quite conveniently under various conditions of application, as hereinafter explained.

The following tables show the percentage of hydrolysis obtained under various conditions:

TABLE 1 Hydrolysis of aqueous alkaline solutions of S -dcetylmercaptoacetamide A-AMBIENT TEMPERATURE.

Goncentra- Concentratlon of tion of Time, Percent Final Hydrolytlc agent theproduet the base min. HydrolpH- ln gram m gram ysls value mol/l. mol/l p a 0.7 1.2 I g 8 Mondethanolamtne. 0.7 0.9 B-TEMPERATURE OF 40 0.

. Ooncentra- Concentra- I tion of tion of Time, Percent Final Hydrolytlc agent theproduct the base min. HydrolpH- 1n gram in gram ysls value mol/l. mol/l.

' 0.5 0.5 15 70 8.1 Ammmia i 0. 5 1 15 as 8.8

The data obtained with S-acetyl-N-methyl-mercaptm acetamide and S-acetyl-u-mercaptopropionamide are similar to those set forth in Table I under the same exp te wns ti TABLE II Hydrolysis of S-succinyl mercaptoacetamide (S-B-carboxypropanoyl-mercaptoacetamide) AAl\iBIENT TEMPERATURE USING AMMONIA AS HYDROLYTIC AGENT Concentration of the Concentration Time, Percent Final product gram moi/l. of NH; in min. Hydrolysis pH- gram moi/l. 7 value B-TEMPERA'IURE OF 50 0.

Concentration of the Concentration Time, Percent Final product gram. mol/l. oi N113 in min. Hydrolysis pH- gram mol/l. value 0.65 0. 65 20 3O 4. 8 0.65 1 2O 58 5. 9 0.65 l. 20 20 89 7. 7

It will be seen from these data that the said products permit; by their alkaline hydrolysis, the production of aqueous solutions containing the corresponding mercaptoamides at different concentrations and pH values, and such solutionsmay. be selected in dependence upon the desired result.

It should be noted that, more especially in the case of the use of S-succinylqnercaptoacetamide, that it is even possible, by a suitable adjustment ofthe quantity of the base employed; to obtain an aqueous solution of. mercaptoacetamide of an acid pH value.

Accordingly, the present invention further includes compositions suitable for softeninghair, as a step in, the permanent waving, comprising in aqueoussolution a compoundofgeneral Formula I and an alkalizing agent, particularly ammonia or an ethanolamine.

The ability of the compounds of general Formula I to give the desired mercaptoamides readily and in good yields may be utilised in practice to obtain a permanent wave in accordance with the various methods hereinafter briefly described.

Thus, in accordance with a first embodiment of the process of, the .inventiomthere isappliedtothehair an aqueous solution preparedat the time of use, by simply dissolving the compound of general Formula I in powder form in the desired quantity of water containing the calculated quantity of the base. Such solutions can be employed in the usual'manner for the permanent waving of hair.

In accordance with a second embodiment of the same process, the hair may be impregnated with a non-alkaline aqueous solution of one of the aforesaid compoundsand then, after winding the hair on curlers, the hair may be saturated with an appropriate alkaline solution. In this case, theliberation of: the various mercaptoacetamides': takes place on the hair itself. I

Various waving methodsmay be employed in accordance with the temperature at which it is desired to apply the process. Thus, for example, a so-called cold wave may be efiected at room temperature, a permanent wave may be effected under a hood ('45 C.); or a tepid wave may be effected (60-80 C.).

Exemplary compounds of general. Formulalaccording to the inventionare as follows:

COMPOUND A S-acetyl mercaptoacetamide having the formula: CH COSCH CONH (i) Method of production: Into a round-bottomed flask equipped with a stirrer, a thermometer, a reflux condenser and a dropping funnel is introduced-onegrammolecule of mercaptoacetamide, and one gram-molecule of acetyl chloride is added drop-wise under stirring, the temperature being maintained between 35 and 45 C. At the end of the operation the mixture is kept stirred for some time, and the hydrochloric acid formed during the reaction is then removed under moderately reduced pressure. The product obtained is then distilled in vacuo. It boils at 132135 C. under a pressure of 1 mm. Hg. The distilled product crystallises, After, recrystallisation from absolute alcohol, a product is obtained which melts at 78-80 C.

The yield is of the, order of 85% of the theoretical yield, and analysis of the product gives:

Percent Nitrogen calculated for C H NO S 10.52 Nitrogen found 10.35

(ii) Alternative method of production: Into a roundbottomed flask equipped with a stirrer is introduced 1 gram-molecule of mercaptoacetamide, and 1 gram-molecule plus a 10% by weight excess of acetic anhydride is added drop-wise. The reaction is exothermic. The temperature is maintained at C. by cooling. At the end of theaddition, the mixture is heated at 50-60" C. for /2-1 hour and then allowed to cool.

The S-acetyl-mercaptoacetamide partly crystallises. The acetic acid formed, and the excess of acetic anhydride, are distilled off in vacuo, and the residue is recrystallised from aboslute alcohol or from a mixture of alcohol and benzene. The yield is the same as for methodti) but the product neednot inthis case be distilledbutcanbe directly isolated...

COMPOUND B.

S-acetyl-N-methyl-mercapto-acetamide of theformula: CH COSCH CONHCH It is-then-possible either to distil theproduct, which" boils fat 131-134 0 under 3 mm. Hg, or to recrystalliseit'diretly from benzene; it has a melting point of'72" C.

The. yield calculated from the N--methyl-mercapto-acct-- amideemployed is 71%.

COMPOUND C S-acetyl-mcrcapropropionamide, of the formula:

CH;CH-'C ONE;

Into a' round-bottomed flask equipped witha' stirrer, a thermometer,a condensingdevice-and a dropping funnel isintroduced asuspension; of 1 gram-molecule of;

a-mercaptopropionamide in 200 cc. of benzene. 1 grammolecule plusa 10% by weight excess of acetic anhydride is added under stirring: The reaction is only slightly exothermic andfno' cooling is required. After the-end of theaddition, the reaction mixture is heatedat about C": for 1 hour under stirring.

The liquid separates into two layers.

The benzene and.the acetic acid. formed-are distilled.

off and the residue is then distilled. B.P.: 114-119 C/0.7mm. Yield: 40%. On cooling, the amide crystallises; melting point: 74 C; (after recrystallisation from'benzene).

set-ting is effected in the usual manner.

garters COMPIOUND D S-succinyl-mercaptoacetamide (i.e. S-B-carboxypropanoyl-mercaptoacetamide of the formula: I I

' HooccmoincoscmcoNH,

Analysis: I .7 Percent N calculated for C H O NS 7.33 Nfound 7.03

The following examples will serve to illustrate the process according to the invention. All these examples concern only the operation of curling hair on curlers, that is to say, the operation concerning the softening of the keratin. The subsequent operation for settingthe shape imparted to the, hair, after rinsing, is carried out in known manner and needs'no further information.

EXAMPLE I A solution having the following composition is prepared in the cold at the time of use:

G. S-acetylmercaptoacetamide 9 Triethanolamine 12 Water to make 100 cc.

The hair is impregnated with this solution by the usual method employed in cold waving. The solution is then allowed to act for -25 minutes and setting of the hair is carried out in the usual manner. A stable permanent wave is thus obtained.

1 EXAMPLE II Under the same conditions as mentioned in Example I, there is applied to the hair a solution having the following composition:

G. S-acetylmercaptoacetamide 9 20% ammonia 7 Water to make 100 cc.

This solution is allowed to act for 10-25 minutes, and There is thus obtained a very tight wave.

EXAMPLE HI G. N-methyl-S-acetylmercapto-acetamide 10 20% ammonia 9 Water to make 100 cc.

The hair is then set by the usual method with the aid of an appropriate oxidising agent. An excellent wave is thus obtained.

EXAMPLE 'IV Under the same conditions as in Example I, there is applied to the hair a solution having the following composition, prepared immediately before application Ssuccinyl mercaptoacetamide -e' 1125 (S-fi-carboxypropanoyl mercapto-ac'etamide) 20% ammonia 16.5 Water to make cc. it is allow'ed'to act for10 to 20 minutes at ambient perature and, after setting with the aid'of'a conven-' tional oxidising agent, a permanent wave-of good stabilityis obtained. a

EXAMPLE V An aqueous solution containing 8% by, weight of S- acetyl me-rcaptoacetamide and 24% by weight. of tn'ethanolamine is applied 'bythe so-called hood? waving technique. The temperature of the locks of hair is 40w 45 C. The solution is allowed to act for 5-10 minutes.- A very satisfactory wave is obtained.

EXAMPLE VI An aqueous solution containing 6% by weight offS- acetyl-mercaptoacetamide and 12% by,weight of triethanolamine is applied by the so-called hood method. The temperature of the locks of hair is 40-45 C. The solution is allowed to act for 10 to 20 minutes, whereby a very satisfactory wave is obtained.

EXAMPLE VI I There is applied to the hair by the method usually adopted in the so-called hood waving, an aqueous solution containing 9% by weight of S-acetyl-mercaptoacetamide and 12% by weight of triethanolamine, for 8' to 15 minutes. The temperature of the locks of hair is from 40-45 C. An excellent wave is obtained.

EXAMPLE VIII There is applied to the hair for 20 minutes by the socalled hood waving method an aqueous solution containing 9% by weight of S-acetyl mercaptoacetamide and 7% by weight of 20% ammonia. An excellent wave is obtained.

EXAMPLE IX EXAMPLE X Under the same conditions as in Example IX, an aqueous solution containing 5% by weight of S-acetylmercaptoacetamide and 15% by weight of triethanolamine is applied to the hair and allowed to act thereon for 5-10 minutes. The temperature on the locks of hair is from 70-80 C. An excellent wave is thus obtained.

EXAMPLE XI An aqueous solution containing 9% by weight of S- acetyl-mercaptoacetamide is prepared and the hair is impregnated therewith. The hair is thereafter wound on curlers and, in a second step, it is saturated with a 10% by weight monoethanolamine solution. After 15 to 20 minutes under a hood, the hair is set and a valuable wave is thus obtained.

EXAMPLE XII Under the same conditions as described in Example X[, the hair is first impregnated with an aqueous 13% by weight solution of S-succinyl-mercaptoacetamide (i.e. S 13 carboxypropanoyl mercaptoacetam-ide) and, after winding of the hair on curlers, it is again impregnated with an ammonical solution containing 11% by weight of 20% ammonia. After contact for 10 to 20 minutes under 7 a: drying hood, and after setting, an excellent wave is obtained.

What we claim is:

1. A. freshly" prepared composition suitable for" ap- V plication to hair as a step in the permanent waving there-t of comprising, in aqueous solution a mercapto derivative of thegeneral formulas.

where R is a radical selected from the groupconsisting of a lower alkyl group having from 1 to 3 carbon atoms and a carboxy alkyl grouprhavingi from 2, to 5. carbon atoms and R and. R are; members. selected' from the group consisting of hydrogen and a lower alkyl residue containing from lto 3 carbon atoms and a'nitrogenbase, said composition having a.pH Within the range of about 5 to 9.5, the amount.of;nitrogen1base being from 1 to 5 moles and preferably of 1 to 3 moles, per mole of mercapto derivative.

2; A process for the so-call'ed' permanent waving of hair wherein the hair is impregnated with a freshly prepared aqueous solution of: a mercapto derivative of the general formula where R is a radical selected from the group consisting of a lower alkyl group having from 11 to 3 carbon atoms andra oarboxyalkyl group having from 2 to 5 carbon atoms and R and R are members selected from the groupconsisting of hydrogen and. a lower alkyl residue containing from 1 to,3 carbon atoms andanitrogenous base ,Tsaid composition having a pH within the rangeof about} to 9. 5, the amountvofznitrogen base beingfrom 1 to 5 mo les, preferably of l to 3 moles, per, mole of mercapto derivative;-restraining said hair to a desired configuration and setting'it in said"configuration.

3. A composition according to; claim 11 wherein: the basic substanceisrammonias r 4. A composition according to. claiml 1 wherein the basic substance is an etlfanolamine;

SZ A mercapto; derivative of the general formula whereiRais: axadicahseIected from the: group. consisting of'aglowerralkyl grouphaving from .1 to 3 carbonatoms andfia .carboxyalkylfgroupf having. from 2-. to: 5 carbon atomsand R and: R5: are; members; selected from. the group consisting; of: hydrogerr' and. atlower alkyl residue containing rom:1:tcx3 Ec'arborratoms:

6. S-acetyl-mercaptoacetamide.

7. S-acetyl-N-methy1-mercaptoacetamide.

8; S-acetyl-alpha-mercaptopropionamide.

9i S-succinylmercaptoacetamide. (S-fl-carboxypropanoyl-mercaptoacetamide.

References Cited in the file offthis patent UNITED STATES PATENTS 2,41'2g700 Weissberger etal Dec. 17, 1946 2,574,996 Allen et'al. Nov: 13, 1951 FOREIGN. PATENTS 1,048,389 Germany Jan. 8, 1959 

1. A FRESHLY PREPARED COMPOSITION SUITABLE FOR APPLICATION TO HAIR AS A STEP IN THE PERMANENT WAVING THEREOF COMPRISING, IN AQUEOUS SOLUTION A MERCAPTO DERIVATIVE OF THE GENERAL FORMULA 